Weeds are the unwanted substances that grow in the field and the disadvantages they cause are 1    hindrance in the growth of the required agricultural field. 2    reduces the fertility of the land.  3     makes the area or the part of the land unavailable for agricultural practices.  

A selective permeable membrane maintaining the integrity of the cell constituents and provide a medium for different organelles to play their role as well as act as a barrier between outer and inner membrane is called a cell membrane.